Fuel tank that is. Not sure I even need one yet, but if I do .... I'll be deciding. One doen't rust, but either one will likely out last me. Auto Krafters is a nice drive from here, & they have the poly in stock.

Just fishing for pros vs cons?

 

X2 poly does not rust. EVER. You have to make sure and get a good ground wire to the sending unit. And make sure to add some of "The Right Stuff" to the sending unit area, when installing to make sure and leak proof it. Since it is a metal sending unit body into a plastic hole? Unless maybe you get one that has a metal seat area imbedded in the plastic hole area?

 

Hell no, don't do this

 

To tell the whole truth, I was under there looking for sign of leak due to smelling fuel, and due to mud and rain, kind of rushed and didn't have a mirror handy, and wondering now if maybe that sender joint is where it might be seeping out some. Getting ready to go visit family, so I'll have to come back to it later.

 

I think I have poly on mine as well I'll have to look tomorrow. I had a gas smell issue recently as well when putting on new caps. Poly is probably better cause of the whole rust thing but a rock will rub its way through either.

 

Well ok why not? If you have a difference of opinion or a different experience, please let us/me know why not. I am open to learning something new and having something different to try. I suggested that because that is the only thing that stopped the drip leak on my 71 Bronco rock crawler's steel aft tank.

I tried a different tank, a different sending unit, a new o ring. I tried adjusting the locking tabs, tried a different lock ring. The Right Stuff is the only thing that stopped the drip leak.

 

RTVs and TRS aren't compatible with gasoline, your sending unit comes with a gasket

 

Well maybe so, but it worked on my Bronco. Guess I am just lucky.

No I did not try this. https://www.autozone.com/sealants-gl...E&gclsrc=aw.ds

Or this. https://www.tanksinc.com/index.cfm/p...rod/prd552.htm

 

RTV silicone does not fully set up in the presence of gasoline.

I'm using this stuff since ethanol, "e-seal", gasoila products are old school from the fifties I think.
https://fedpro.com/products/gasoila%...thread-sealant

 

What if it has time to set up/cure before you introduce gasoline (fumes or actual fluid) to it? That seems to have worked for my issue.

 

That makes sense to me, Rich. Ethanol, what a mess that industry has made.
How have you been Rich? How old is your Grandson now ? We've got two more great grandchildren since we talked last. Time to catch up brother, besides I'm going to need some parts and you can pay for the grand kids college

 

I had a crack on my aft gas tank on my '86 that I just slapped some JB weld on and called it good. Drove it 1800 miles across the country shortly after with no issues.

 

Redroad PM sent to catch up.

 

Tonite watching Perry Mason, I happened to drift a thought to gas caps My '77 is a non-evap truck, so the cap should just allow air in under vacuum as the fuel pump pumps gas out. I recalled the original gas cap almost alwas went "pfffffft" as I opened it slowly, letting me know was some little pressure in there. I replaced it a couple years ago with a Stant 10749 (box said CarQuest, same), I still have the box with the original cap in it. The original has a dried cracked gasket. Tonight I looked in my cabinet, found a couple MotoRad MGC749 caps, they differ slightly from the Stant in that they have thicker rubberier gaskets and the valves are in a deep tan plastic enclosure. The Stant has the two extra deeper reaching catches and the valve in in a metal enclosure, and it advertises "anti-surge" Anyway, I put a new MotoRad on it,we'll see if that holds any pressure. If it does, I have no leaks. I'm not worried about too much pressure, the carburetor inlet needles/seats will limit any internal pressure ... as always they did. If I find it builds a little psi, I'll know the smell was not from a leak, and then I'll put the Stant back on maybe.

Update 12-28-2023: I found the original Ford cap in a box behind the seat, it's simply marked "PRESSURE" and 'VACUUM" on opposing sides, the finger tabs are not bent like many do, It's valve assembly is in a black unmarked plastic enclosure. Using a hose, it will not let pressure pass, but is instantanious in letting vacuum in, very light spring. That gasket is still cracked though.
In further developments, I think I know why there has been no "pfffffft" since just prior to my replacing the OEM with the cracked gasket in 2022 (reciept in box).

• The OEM gas cap has the black plastic valve assy., it's very lightly spring loaded to shut in the absence of vacuum pulling air into the cap. That's why it sealed, it sealed except when vacuum pulled air in.
• Was in early 2022 I bought a Stant (CarQuest) 10749 to replace the OEM, it is a re-boxed Stant 10749. It is the one that says is "anti-surge", it has the two extra legs with dogs to keep the cap from blowing off suddenly when opened if there is pressure. It was bought as I was gonna take the truck to Roy for body & paint and didn't want to stink up his shop. It does NOT use spring pressure to close the valve if no vacuum pulls it open. It just uses the weight of the valve or a ball in there. I can apply suction, it's like absolutely no resistance, none, unlike the OEM. If I blow suddenly, I hear the valve shut with a metalic tick, and it's closed. However... if I very gently and slowly blow into the valve, I can pass air without shutting the valve as long as I keep the gas cap even remotely upright. As soon as the cap is tilted, like it might be in a roll over, it is immediately shut. .
• The MotoRad MGC749 gas caps I accumulated (I think I maybe ordered two by mitsake) in 2023 thinking the CQ was defective ... operate like the OEM one, they are spring loaded valves that shut in the absence of a vacuum, but they do seem slightly stronger in spring force. If there is no vacuum, they stay shut. I did put one on yesterday, removing the CQ one, and by tonight it had developed a very little pressure. The Stant would not have built any pressure unless the truck was overturned, as the slow pressure build up would not be fast enough to close the pressure valve.

So now to decide ... use a MotoRad cap and let it build a little pressure as things warm up, knowing that it will still open to let air in when fuel is pulled out ... or ... use the Stant made CQ cap and accept a whiff of fuel when warm weather causes evaporation. The MotoRad performs just like the OEM did, gas will stay in the tank, the carburetor inlet needle/seats will open if excess pressure builds. I have two MotoRads, so I think there is my answer.

I'll still replace my fill hose, fill vent hose, & fuel line to the frame mount steel fuel line..

 

I have the entire series of Perry Mason.
One of the nurses in the infusion center at Huntsman gave it to me back when I was volunteering.
Such a GREAT show.

I'd go for a poly over metal any time.
Here in Utah poly is short for polygamist.

I ruined the poly tank in my 1979 F-250 cresting the top of White knuckle Hill in Moab
on my first trip to the Moab Jeep Safari back in 1988.